Laid-open Japanese Utility Model Publication No. Sho 57-44063 and Laid-open Japanese Utility Model Publication No. Hei 7-22951 disclose squeeze-type extrusion containers that comprise an inner container body and an outer container body that contains the inner container body.
With the extrusion container disclosed in Laid-open Japanese Utility Model Publication No. Sho 57-44063, a ventilation hole is provided at the bottom part of a main container body so that after extrusion of contents by squeezing of the main container body, external air is introduced between an outer container body and an inner container body so that while keeping the deformed shape of the inner container body as it is, the main container body is returned by its restoring force to its original shape.
With the arrangement of Laid-open Japanese Utility Model Publication No. Hei 7-22951, an outer container body and an inner container body are joined and fixed together, and a first non-return valve, allowing the passage of contents from the inner container body but preventing the entry of external air into the contents, and a second non-return valve, allowing the passage of external air between the outer container body and the inner container body but preventing the extrusion of external air that has entered between the outer container body and the inner container body, are provided.
Also, a method, wherein a pair of adhesive bands of longitudinal band form, each of which adheres and fixes an outer container body and an inner container body together along the entire height range of a main container body, are provided to restrict deflation of the inner container body to a fixed form with which shrinkage in the height direction does not occur, thereby securing a flow path and smoothening the extrusion operation, is also generally used.
In order to make adhesive bands such as described above function as a means for securing a flow path, it is simple and effective for example to dispose at least two adhesive bands at axially symmetric positions with respect to the central axis of a container body. However in regard to the width dimension of each adhesive band, if the width is too wide, adequate deflation of the inner container body cannot be accomplished, and oppositely if the width is too narrow, the flow path for the contents will become closed by deflation at an early stage, consequently preventing smooth extrusion operation and causing the amount of unused contents to become high.
This invention has thus been made to resolve the above-described problems of the prior art and an object thereof is to provide a squeeze-type extrusion container of excellent extrusion property that enables extrusion operations to be performed smoothly up to the final stage and enable the remaining amount of contents to be lessened.